In a 5-gallon food-grade bucket, combine the sliced cucumbers, salt, onion, and bell peppers. Stir so the salt is evenly distributed. Cover the cucumber mixture with a clean kitchen towel or tea towel, and place a few inches of ice on top of the towel. Allow to sit for 3-4 hours in a cool place.
Drain the vegetables and set aside. Make the brine by bringing the vinegar, sugar, cloves, mustard seeds, celery seed, and turmeric to a boil in a large pot over high heat. Meanwhile, prepare a boiling water canner. Heat the jars in simmering water until ready for use. Do not boil. Wash the lids with hot soapy water. Set bands aside.
Place an equal amount of cucumbers, onions, and bell peppers into each hot jar. Press down the mixture, as it will rise when you pour in the brine.
Use a wide-mouth funnel, ladle hot pickling liquid over top of the cucumbers, leaving a 1/2-inch headspace. Remove any air bubbles. Wipe the rims with a clean, damp paper towel. Center the lids on the jars. Apply the bands until the fit is fingertip tight.
Process jars in the boiling water canner for 10 minutes, adjusting for altitude. Remove the jars and allow to cool completely on the counter for 24 hours. Check the lids for seal. The lid should not flex up and down when the center is pressed.
For best flavor, let stand for 3-4 weeks before enjoying. Store the jars in a cool, dry place for up to 1 year. If a jar doesn't seal, store in the refrigerator and use within 3 months.